Answer:
Step-by-step explanation:
Multiply through by the L. C. M which is PS.
1/p*ps+1/s*ps=1*ps
P+p=ps
2p=ps
Divide both sides by 2
2p/2=ps/2
P=ps/2
Answer:
Step-by-step explanation:
Answer:
The score that separates the lower 5% of the class from the rest of the class is 55.6.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question:

Find the score that separates the lower 5% of the class from the rest of the class.
This score is the 5th percentile, which is X when Z has a pvalue of 0.05. So it is X when Z = -1.645.


The score that separates the lower 5% of the class from the rest of the class is 55.6.